An endoscope is an elongated instrument used in both medical and industrial applications for visualizing and operating on hard to reach areas such as, without limitation, a lumen within a body or an industrial pipe. With regard to medical applications, endoscopes can be used for a variety of different diagnostic and interventional procedures, including colonoscopy, upper GI endoscopy, bronchoscopy, thoracoscopy, laparoscopy and video endoscopy.
Colonoscopy, as one example for use of an endoscope, is a medical procedure in which a flexible endoscope, or colonoscope, is inserted into a patient's colon for diagnostic examination and/or surgical treatment of the colon. A standard colonoscope is typical 135-185 cm in length and 12-19 mm in diameter, and includes a fiber optic imaging bundle or a miniature camera located at the instrument's tip, illumination fibers, one or two instrument channels that may also be used for insufflation or irrigation, air and water channels, and vacuum channels. The colonoscope is usually inserted via the patient's anus and advanced through the colon, allowing direct visual examination of the colon, the ileocecal valve and portions of the terminal ileum. Insertion of the colonoscope is complicated by the fact that the colon represents a tortuous and convoluted path. Considerable manipulation of the colonoscope is often necessary to advance the colonoscope through the colon, making the procedure more difficult and time consuming and adding to the potential for complication, such as intestinal perforation.
Steerable colonoscopes have been devised to facilitate selection of the correct path through the curves of the colon. However, as the colonoscope is inserted further and further into the colon, it becomes more difficult to advance the colonoscope along the selected path. At each turn, the wall of the colon must maintain the curve in the colonoscope. The colonoscope rubs against the mucosal surface of the colon along the outside of each turn. Friction and slack in the colonoscope build up at each turn, making it more and more difficult to advance and withdraw the colonoscope. In addition, the force against the wall of the colon increases with the buildup of friction. In cases of extreme tortuosity, it may become impossible to advance the colonoscope all the way through the colon.
Through a visual imaging device on the distal tip of the colonoscope, the user can observe images transmitted from the distal end of the colonoscope. It is primarily from these images and from the user's general knowledge of the colon's basic anatomical shape that a user attempts to guide the colonoscope through the tortuous path of the colon. Despite her knowledge, skill and best efforts the user can become very disoriented within the three-dimensional space of the colon with only a camera to visualize and orient the steerable distal tip of the colonoscope. For example the user may need to remove a polyp and have a difficult time reorienting herself as to which way is forward; the user may have caused the camera to rotate in space, for example by “torqueing” the proximal end of the scope, and this alone or in combination with bending the steerable distal tip can also result in a loss of orientation. A loss of orientation frequently requires the user to withdraw the colonoscope a certain distance to re-orientate the user. Reorientation of the user results in increased procedure time, which increases patient discomfort and increases the amount of time spent treating the patient with concomitant loss of throughput and revenue for an endoscopic treatment center.